Fastener head



FIG. 1 is a perspective view of the fastener head constructed in accordance with the new design;

FIG. 2 is a top plane view; and,

FIG. 3 is a front elevational view, with the back, left, and right elevational views being mirror images thereof.

The elements illustrated in dashed lines in the accompanying drawings are considered environmental and do not form a part of the claimed design. 

The ornamental design for a fastener head, as shown and described. 